Income per head in Equatorial Guinea is more than $30,000 (£18,450) a year. No, that's not a misprint. On average, incomes in the west African country are as high as they are in Italy or Spain.

Equatorial Guinea is also mired in poverty. Most of its citizens live on less than a dollar a day and its infant mortality rate is the fourth worst in the world. The average per capita income, in other words, disguises the fact that a tiny elite is stupendously rich, while the rest of the population struggles to survive.

What's more, the explanation for this disparity is simple. It can be explained in two words: oil and corruption. Teodoro Nguema Obiang, is officially the forestry and agriculture minister of Equatorial Guinea on a salary of $4,000 a year but has a $35m home on Malibu Beach in California. Obiang is tipped to be the country's next president when his father dies.

For too long, governments in the west turned a blind eye to what was going in countries like Equatorial Guinea, just as they kept quiet about the millions being salted away by Hosni Mubarak of Egypt and Zine al-Abidine Ben Ali of Tunisia. The basic principle adopted has been drearily familiar: "He's a son of a bitch but at least he's our son of a bitch."

But recent events in Cairo and Tunis have exposed the folly of this approach. The causes of the popular unrest in north Africa and the Middle East are many, yet it is clear that one factor has been disgust at the obscene levels of corruption.

In theory, a clean-up plan for global politics is in train. Last November, the meeting of the G20 group of developed and developing countries agreed in Seoul a comprehensive anti-corruption action plan, designed to promote the rule of law, prevent funds being illegally transferred to western banks, protect whistleblowers and make financial systems trustworthy and transparent.

It is important that this action plan is implemented because the stakes – both political and economic – are high. Africa, for example, is the world's poorest continent but is rich in natural resources. It has 10% of the world's oil reserves, 40% of gold, and more than 80% of chromium and aluminium. This buried treasure could be either a blessing or a curse: it has the potential to accelerate development if used properly, but it could also prompt a fresh wave of murky deals between corporate executives and corrupt officials. Already, one-in-four oil dollars from Angola goes missing, while Nigeria's own corruption agency estimates that up to $400bn of oil money has been filched or wasted in the past 50 years.

This is happening at a time when austerity programmes in the west are making international aid a much tougher sell. In the UK, development assistance is one of only two budgets, along with health, ringfenced from spending cuts – though the development secretary, Andrew Mitchell, is aware that he has to prove to sceptical voters that he is getting value for money.

"Achieving transparency in the exploitation of mineral resources is one of the most fundamental aspects of development," Mitchell said last year. "If our taxpayers are supporting poverty reduction strategies in countries with significant resources interests that are not being used in the people's interest, that will bring our use of taxpayers' money into massive disrepute."

The government now has a chance to put Mitchell's fine words into practice. Nicolas Sarkozy, the French president, wants the European Union to adopt, as quickly as possible, legislation that would force industries in the extractive sector to disclose all their payments in every country in which they operate. This would replicate provisions in the Dodd-Frank financial reform bill passed in the US last summer, which covers UK companies such as BP that are listed on the New York stock exchange.

Britain is minded to support Sarkozy's proposal. The rock star Bono lobbied for it when he met David Cameron at the World Economic Forum in Davos. Bono's campaign group, One, has since had follow-up talks with George Osborne. Vince Cable, the business secretary, says he is in favour of the initiative and the Treasury has made similar noises. Ministers are expected to voice their support at an experts' conference Sarkozy has organised in Paris to discuss the issue next week.

Cable says that so far he has had no push back from UK companies, which is somewhat surprising. There is a new "Scramble for Africa" going on for control of natural resources and it probably won't be long before corporate lobbyists suggest that tough European disclosure rules would leave the field open for China. The government will also, doubtless, be suspicious of signing up to legislation originating in Brussels, and will want to explore the alternative of passing its own law.

Given the political will, these objections could easily be overcome. The case for Europe-wide legislation is twofold: it would cover all companies operating in Europe, such as Russia's Gazprom, and it would act as a spur to the rest of the G20 to fall into line. Many of China's largest resource companies, such as Petrochina, are already covered by the Dodd-Frank legislation, and seem quite prepared to comply with the same disclosure standards as companies in the west.

The benefits of a more transparent regime are considerable. Western governments would find less pressure on aid budgets if more of the natural resource wealth of developing countries were used for development. There would be less talk of aid being the transfer of money from poor people in rich countries to rich people in poor countries. Companies that engaged in best practice would benefit at the expense of those that behaved badly. There would be a more stable investment climate. Corruption would be much easier to monitor and curb. Above all, it would ensure that the poor get a fair share of the natural resource bounty. Between 2000 and 2008, mineral resources accounted for almost a quarter of Africa's growth, but the real beneficiaries were corporations and political elites. The Democratic Republic of the Congo is rich in minerals but in 2006 its treasury received the princely sum of £86,000 in mineral rights. Speaking from South Africa last week, Bono said that tackling corruption is as big a deal as debt relief and time for "business to work for the poor as well". He's absolutely right about that. For too many countries, natural resources have been a curse rather than a boon, but it doesn't need to be that way. If ministers show the courage needed to bring about change, they should expect loud applause.